Analytical Sciences

A Carbon Dots-based Fluorescence Turn-on Method for DNA Determination

WenJun BAI, HuZhi ZHENG, YiJuan LONG, XiaoJiao MAO, Mei GAO, and Lingyan ZHANG

Key Laboratory on Luminescence and Real-Time Analysis (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Beibei, Chongqing 400715, P. R. China

In the present work, we found that methylene blue (MB) caused an efficient quenching of the fluorescence of carbon dots (CDots). However, as ct-DNA was added, the fluorescence of CDots was restored reversibly. Under the experimental conditions, CDots were excellent electron donors. MB adsorbed on the surface of CDots and quenched the fluorescence of CDots through an electron-transfer process; and then the addition of DNA caused a restoration of the CDots fluorescence intensity, since DNA could bind with MB and remove it from the CDots. Based on this phenomenon, we developed a new system for DNA detection. A sensitive detection of ct-DNA with a detection limit of 1.0 × 10⁻⁶ mol L⁻¹ and a linear detection range from 3.0 × 10⁻⁶ to 8.0 × 10⁻⁵ mol L⁻¹ with a relative fluorescence intensity of CDots were achieved. To the best of our knowledge, this is the first use of CDots for DNA detection.

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